[identity] Copy google_auth_provider from Topaz

Comments

[identity] Copy google_auth_provider from Topaz
This is step 1 of 4 in a soft transition to migrate the Auth Provider
between repos. It creates a new component but the component is not yet
included in any configurations or used.
Change-Id: I3b115347b16129b0be72d7ff1c59310d4105573d